Machine tool



Nov. 7, 1939. s. K. McKEE El AL 2,178.915

MACHINE TOOL Filed Feb. 28, 1936 8 Sheets-Sheet 1 INVENTORS -GEORGE K. MCKEE CHARLESE. Beg N/TT Nov. 7, 1939- G. K. McKEE ET AL MACHINE TOOL Filed Feb. 28, 1936 8 Sheets-Sheet 4 Giana E K. McKE'E Cmaus E. BEnnn-r Q ATTORNEYS Nov. 7, 1939.

MACHINE TOOL Filed Feb. 28, 19 36 8 Sheets-Sheet 6 Nov. 7, 1939. a, K, McKEE :1- AL 2,178,915

MACHINE TOOL Filed Feb. 28, 1936 8 Sheets-Sheet'7 INVENTORS Geo/m: K MCKEE CHARLES E. Bs/uwrr W 7 l a E Nov. 7, 1939. G, K, MOKEE ET AL 2.178.915

MACHINE TOOL Filed Feb. 28, 1936 8 Sheets-Sheet 8 GEORGE K. Mc KEE (Zn/muss E. 551mm ATTORNEY 5! WMa/WW Patented Nov. 7, 1939 I PATENT oFFics MACHINE TOOL George K. McKee and pharles E. Bernitt, Cincinnati, Ohio, assignors to The Avey Drilling Machine Company, Covington, Ky., a corporation of Ohio Application February 28, 1936, Serial No. 66,263

29 Claims.

This invention relates to improvements in machine tools and particularly to improvements in drilling machines.

One of the principal objects of the present in- 5 vention is the provision of an improved control mechanism for controlling the movement of the tool in such machines.

Another object of the invention is the provision of an improved hydraulic control circuit for 10 efiecting and controlling the various movements of a tool or drill relative to a work-piece.

A further object of the invention is the provision of a machine tool or drilling machine particularly adapted for drilling long or deep holes l5 and in which the tool or drill may be repeatedly actuated through and from the work during the tooling or drilling of said long or deep hole.

A still further object of the invention is the provision of adrilling machine having the drill thereof actuated through a series of steps while boring or drilling a relatively long or deep hole and taking advantage of the thrust set up during the drilling or cutting of the work to effect automatic clearing of the chips from the hole 3 thereby materially increasing the life of a drill or tool and reducing the breakage thereof to a minimum.

A still further object of this invention is the provision of an improved hydraulic control cir- 30 cuit and mechanism therefor which will materially simplify the production of such a mechanism without sacrificing in the least the efficiency of such a circuit.

It is also an object of this invention to pro- 35 vide a multiple drilling machine in which the individual spindles or tool carriers of each drilling machine are hydraulically actuated independently of the other spindles and without effecting their operation.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification considered in conjunction with the accompanying drawings forming a part thereof and it is to be understood that -1 any modifications may be made in the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

so In the drawings:

Fig. 1 is a front elevation of a drilling machine embodying the improvements of this invention;

Fig. 2 is a side elevational view of the machine shown in Fig. 1;

Fig. 3 is an enlarged side elevational view of the drill head which encloses the hydraulic control and operating mechanism;

Fig. 4 is an enlarged top plan view of the head as seen from line 4-4 on Fig. 1;

Fig. 5 is an enlarged fragmentary sectional 5 view through the head as seen from line 5-5 on Fig. 1; I

Fig. 6 is an enlarged sectional view through the head and illustrating the control valves as seen particularly from line 66'on Fig. 1;

Fig. '7 isa sectional view taken at right angles to Fig. 6 and as seen from line |'I on said Fig. 6;

Fig. 8 is a fragmentary elevational view of certain parts of Fig. 7 as seen from line 8-8 on said Fig. 7 l5 Fig. 9 is a view partly in section and partly in elevation of the pilot valve and control mechanism therefor, said parts being further illustrated in dotted lines in Fig. 3;

Fig. 10 is an enlarged fragmentary sectional view-through the drive mechanism for the spindle as seen from line lll--lll on Fig. 1;

Fig. 11 is a fragmentary sectional view of the final stop ledge as seen from line I l-I l on Fig. 3;

Fig. 12 is a sectional view takenin a plane ahead of Fig. 6 and illustrating the control mechanism for a stage drilling mechanism, that is, a mechanism for effecting step by step drilling through a long or deep hole;

Fig. 13 is a view partly in section and partly in elevation illustrating the connection between the stage drilling mechanism and the normal control mechanism;

Fig. 14 is a side elevational view of the drill head, similar to Fig. 3, illustrating the operating mechanism for the stage drilling machine;

Fig. l5'is a detail sectional view taken on line l5-I5 on Fig. 14;

Fig. 16 is a detail sectional view taken on line Iii-l6 of Fig. 14;

Fig. 17 is a detail sectional view taken on line ll-|'| of Fig. 14;

Fig. 18 is a vertical detail sectional view taken on line |8l8 of Fig. 14;

Fig. 19 is an hydraulic diagram illustrating the hydraulic circuit for a single spindle utility drilling machine;

Fig. 20 is an hydraulic circuit diagrammatically illustrating the control mechanism for a single spindle drilling machine with the stage drilling attachment coupled thereto;

Fig. 21 is an hydraulic circuit diagrammatically illustrating a general purpose machine including 3e plurality of spindles here shown as two in num- Fig. 22 is an hydraulic circuit tically illustrating a drilling machine having a plurality of spindles, here shown as two in number, to each of which spindles is coupled a stage drilling attachment; and

Fig.23isafragmentary sectional view through the slip dog moimting as seen from line 28-28 on Fig. 14.

Throughout the several views of the drawings similar reference characters are employed to denote the same or similar parts.

In the drawings the structural elements are' -lng machine, each spindle having a stage drilling attachment thereon, may be provided, in accordance with the diagrammatic hydraulic circuit.

As seen in Figs. 1 and 2, the drilling machine comprises a base 25 from which rises a standard 26 having formed along its forward face a V- shaped dovetail 21 for the work-supporting table 28. Any suitable or desirable means may be provided for adjusting the table 22 relative to the way 21 and for locking the table in adjusted positions.

Secured to the upper end of the standard 28 is a column 29 having a gooseneck III which has secured to it or integral therewith a housing 3| which overlies the table 28. The housing 1| encloses the motor and driving mechanism for rotating the spindle and these parts are shown in section in Fig. 10. As shown in this figure, the housing 3| is provided with an upper cap plate 22 and a lowercap plate 23 each providing antifriction bearings for a shaft 24. The shaft 34 constitutes the motor shaft and has' secured thereto an armature I5 and fan blades 38. The upper end of the shaft 24 projects into the cap plate 32 and has keyed or otherwise secured thereto a pinion 21 forming one member of a change gear transmission. Meshing with the pinion 31 is a gear 38 keyed or otherwise secured to a driving sleeve 29 rotatably mounted in antifriction bearings carried by the upper and lower cap plates 22 and 33. The sleeve 29 has a spline connection 40 with the spindle 4| which, as will laterbe pointed out, carries a drill or the like at its other end. The upper cap plate 32 is closed by a suitable cover 42 which may be readily removed to permit replacement of the pinion 31 and gear 38 by other gears having a different ratio whereby the rate of rotation of the sleeve-38 and therefore the spindle 4! may be varied. By providing a variable speed motor 35 the said rate of rotation of these parts may be further varied.

Beneath the gooseneck 30 and on the forward iace'thereof the column 29 is further provided with a dovetail guideway 43 to which is secured the drill head indicated in general in Figs. 1 and 2 by the reference numeral 44. As seen in Fig. 4, the drill head is provided in its forward end with a V-shaped guideway 45 receiving a correspondingly. shaped dovetail tongue 48 projecting rearwardly from the spindle carrier indicated in general in the several views of the drawings by the reference numeral". In order to take up any wear and insure accurate movement of the as illustrated spindlecarrier 41 thereisprovidedbetween the dovetail guideway and guide 42 gibs 40 which maybeadjustableintheusual manner.

AsseeninHgJJhespindlecarrierflccm prisesahousing 4! having formedtherethrougn g or the'like II. The lower 4| projects beyond the quill 2 at said projection a t 48 receiving the tapered or f d of a like (not shown).

Thequill i2isadaptedtobesecuredinits various positions of adjustment, and for this reason the housing 42 is split near its lower end In order to actuate the spindle carrier 41 relative to the head 44 the housing 40 of said carrier is provided with a projecting tongue or lug 630 having formed therein a perforation receiving the reduced end 64 of a piston rod 65. The a piston rod i5 carries at its other end a piston M disposed within the bore of a cylinder 67 secured in any desirable manner in a suitable bore formed in the head housing 68. As shown in Fig. 5, the

cylinder 61 is closed at its upper end by a head I. o

in which is formed a port ll communicating with a pipe coupling II for a pipe or conduit 12. The lower end of the cylinder 51 is likewise closed by a head 13 which carries with it a stuffing boxor packing I4 to prevent leakage rod 65, since said piston rod must pass through the head 13. The upper cylinder head ll is se-- cured by means of a plurality of countersunk bolts 15 while the lower piston head is secured by one or more countersunk screws I. passing 0 through a flange Tl integral with and projecting from the head 13. In order to supply actuating fluid to the undersurface of the piston, to be describedin detail later, the head housing I and cylinder 61 are ports 18.

plying the actuating fluid to the ports II and 18 of the cylinder is shown in Fig. 19, and this circuit will now be described, and during the de- 70 scription of said circuit the several control valves will be described in detail with reference to their structural views as they are encountered in said circuit. As seen in Fig. 19, there is provided a sumportank'llwhichmaybeapartoftheu at II. On each side of the split so pastthepiston provided with The hydraulic circuit for controlling and sup- I bed standard 26 or may be a separate tank disposed adjacent the'machine base.25. .Disposed above the said tank 19 is a pump 80 connected with the tank by means of a suctionpipe, 8|. Projecting from the other side of the pump 80 is the pressure pipe or conduit 82 connected through a relief valve 83 with the tank 19. The

Q The starting valve mechanism is structurally illustrated in Fig. 9 and as there shown comprises a housing 81 secured in any desirable manner to an interior wall 88 of the head houing 68. The casing 81 is provided therethrough with a bore into which is secured a valve sleeve 89 which is provided with a plurality of sets of radial ports- 90, 9| and92. Each of these sets of radial ports is encircled by a similar circumferential groove 93 formed in the exterior of the valve sleeve 89.

Disposed within the bore in the valve sleeve 89 is a valve member 94 provided. intermediate its ends with a reduced portion or cannelure 95 adapted in different positions of adjustment to connect the central set of radial ports 9| with the end sets of radial ports 90 and 92.- The valve member 94 therefore has two positions of adjustment, that shown in the drawings and a second position above .that shown, or for connecting the ports 9| and 90. As seeen in Fig. 19,

it is with the ports 90 that the branch pressure pipe or conduit 85 connects, while the ports 9| have connected therewith one end of a pipe or conduit 96 which terminates at its other end in the valve mechanism 84. The remaining set of ports 92 have connected therewith one end of a pipe or conduit 91 which has its other end connected with, as shown in Fig. 19, a pipe-or conduit 98 which terminates or discharges in the sump or tank 19. It should be noted here that the pipe or conduit 98 is merely a drain from the interior of the head housing 68 and that the pipe or conduit 91 instead of being connected with a return drain or pipe merely empties into the interior of the housing itself from which the fluid is drained off.

In orderto shift or actuate the valve member 94 it has projecting therefrom a stem I being provided in one side thereof with a'notch IOI receiving the ball end I02 of a valve shifter member I03. This valve shifter member I03 is keyed or otherwise secured to a stud or shaft I04 ro tatably journaled in a plate member I05 secured to the righthand surface of the head housing 68.

Exteriorly of the said plate member I05 the' shaft or stud I04 has secured to it the hub I06 of the manual starting and stopping lever I01 which terminates at its outer end in a'knob or ball I08. By reference to Figs. 3 and 9 it will be seen that if the lever I01 is actuated downwardly or in a counter-clockwise direction it will effect an elevation of the valve member 94 and thereby Y connection through the reduced portion or cannelure thereof the ports 90 and 9|.

In order to determine the positions of the valve member 94 the stud or shaft I04 has keyed or otherwise secured thereto behind the plate member I05 a detent member I09 having formed in its operative periphery, notches I I0 and III. Co-

operating with said notches H0 and III is thepointed nose "-2 of a dog II3 pivoted at I I4'to the housing wall 88. In order to hold the operative end of the detent plate I09 and dog nose I I2 into engagement with one another the said dog 3 is yieldably actuated through the spring I I5 toward the shaft I04. As will be noted'from Fig. 9, the sides of the notches II 0 and III are arcuately cam shaped and therefore these parts act as the-load and flre dog for firing the valve shifting member I03 past center to itsbperative positions. 9

In the operation of the machine the valve mem- .3, pair of bearings H8 and H9. The inner adjacent edges of the bearings H8 and II9slightly overlie the groove in the side of the carrier to thereby provide a If-shaped slot in which the head I of a clamping screw I2I is seated. The clamp-,

ing. screw I 2| passes through a borein the dog H6 and receives exteriorly thereof a nut for securing the dog in adjusted positions.

The dog 6' has its inner end tapered as at I22 in Fig. 3 for engagement with a shoulder I23 of a flipper I24 pivoted at I25 to the outer surface of plate member I05. The flipper I24 is provided with a notch I26 receiving the ball end I21 of an arm I28 keyed or otherwise secured to the stud or shaft I04.

Shifting of the valve member 94 to its second position, as above described, throws the shoulder I23 of the flipper I24 into the path of movement of the dog nose I22 so that said dog nose at the proper point in the movement of the spindle carrier will shift the said valve member from its starting position to its running position, that illustrated. It should be noted that the shifting of the valve to the running position by the dog II6 changes the rate of movement of the spindle carrier from rapid traverse to feeding;

The control valve mechanism 84 is structurally illustrated in Fig. 6 and as there shown comprises a valve block or housing I29 secured to an inner wall of head housing 68. The valve block I29 is provided with a bore in which is disposed a valve sleeve I30 being provided with a plurality of sets of radial ports I3I, I32, I33, I34, I35, I36, I31, I38, I39, and I40, each set of ports being encircled by a similar circumferential groove I4I formed in the exterior of the sleeve I30. Disposed within the bore in the valve sleeve I30 is a valve member I42 being substantially cylindrical in form and having a plurality of reduced portions or cannelures I43, therein for connecting the sets of radial ports in different combinations depending upon the posi-' I44, I45, and G minating in the sump or tank 19.

have connected therewith one end of a pipe or,

duit Illa. The radial ports Ill and 8 have respectively connected therewith discharge pipes conduit 8 the other end of which is connected with a balance valve mechanism indicated in general in Fig. 19 by the reference numeral 9. The ports I35 have connected therewith oneend of a pipe or conduit I68 which empties into a pipe or conduit I5I. The ports I31 and I39 have respectively connected therewith branch pipes or conduits I52 and I53 having their other ends connected with a pipe or conduit I5l which terminates at the lower end of the piston cylinder 61 and therefore connect with the port 18 thereof.

The remaining ports I38 have connected therewith one end of a pipe or conduit I55 emptying into a pipe vI56 which through its branches I51 and I58 is connected with a back pressure valve indicated in general in Fig. 19 by the reference numeral I59.

In order to connect the various ports of the control valve mechanism in different combinations the valve member Il2 thereof has three operative positions, one of which is illustrated in the drawings; the second position being above that shown and the third position being below that shown. The initial operation of the starting valve member 9l through the lever I81, as above described; connects the pressure in the pipe or conduit 82 through the pipe or conduit 85, valve mechanism 86, and pipe or conduit 96 to the upper end of the control valve member M2 for driving same to its lowermost position which, as will be described later, effects a rapid" downward movement of the piston 66 and therefore the spindle carrier. Upon engagement of the rapid traverse dog II6 of the spindle carrier with the flipper I2l the valve member H2 is shifted to the position shown, which is the feed position. In order to so shift the said valve it has projecting therefrom a valve stem I68 having a shoulder I6I thereon for a guide member I62. The guide member I62 has abutting its undersurface one end of a spring I63 which encircles a projecting reduced portion I6l of said stem. The other end of the spring I63 abuts a bushing, sleeve, or the like I65, threaded into the lower wall of the head housing 68. The movement of the valve member I l2 by the spring I63 is limited by a latch I66 secured to one end of a shaft I61 rotatably journaled in a bracket I68 disposed interiorly of the housing 68. The latch I66 has projecting therefrom a hook or nose I69 engaging 9. lug I18 projecting laterally from the guide member I62. The latch I66 is later retracted to permit the spring I63 to shift the valve member M2 to its third or final position, which is the rapid retracting position. In order to hold the latch I66 in operative position to engage the lug I18 the said latch has connected therewith one end of a spring "I which has its other end connected to a fixed part of the head housing. The upper position of the valve member Il2 as effected by the spring I63 is determined by a plug I12 threaded into the upper end of the valve sleeve I38.

The balance valve mechanism 9 is shown structurally in Fig. 6, and as there shown comprises a valve sleeve I13 pressed into a suitable bore in the valve block I29 and having the opposite ends of the bore therein closed by plugs I" and I15. The sleeve I13 is provided therethrough plained in further detail later. The valve member I8I has projecting from one end thereof an elongated stem I83 which i encircled by 'a spring I8l abutting on one end with the plug I'll and on the other end with the shoulder of the valve member around the stem I83.

By reference to Fig. 19 it will be seen that it is with the ports I18 that the pipe or conduit I ll connects, while with the same ports but on the other side of the valve the said ports are connected through a branch conduit I86with a conduit I 86 terminating on its upper end in an adjustable throttle valve mechanism indicated in general by the reference numeral I81. The pipe or conduit I86 in addition is connected with the ports I19. The ports I16 have connected therewith one end of a pipe or conduit I88 which terminates at its other end in a pipe or conduit I89 extending between the adjustable throttle valve mechanism I81 and the pipe or conduit I5I. The remaining ports I11 have connected therewith the upper end of the discharge pipe or conduit 98. The operation of the balance-valve mechanism H9 is well understood, since it is utilized for maintaining a constant pressure in the circuit as effected and determined by the throttle valve mechanism I81.

This throttle valve mechanism I81 is shown structurally in Fig. 6 and comprises a conical valve member I98 disposed in a correspondingly conically' shaped seat I9I formed in the side of the valve block I29. The valve member I98 is pro-. vided with a counter bore in which is disposed one end of a spring I92 which encircles a valve stem I93 and abuts on one end the base of said counter bore and on the other end with a shoulder I9l the valve member I98. The body portion of the valve member I98 is provided throughout a portion of its periphery with a groove or slot I96 which gradually decreases in depth and width from the starting point to the finishing point of said groove. position changed with respect to the pipes or conduits I86 and I89 (see Fig. 19)'for thereby enlarging or-decreasing the orifice through which the flow takes place from one of these pipes or conduits to the other and thereby controls the amount of fluid to the piston 66 and thereby controlling the rate of actuation of said piston.

As seen in Fig. 6, the valve stem or spindle I93 is rotatably journaled in a bracket or carrier I91 and has projecting from said bracket 2. reduced portion I 98 to which is keyed or otherwise secured a knob, actuating member, or the like I99. It should be noted that at the point where the stem I93 leaves the carrier I91 the said carrier is provided with a stufling box 288 to prevent loss of fluid along the-said stem. The carrier I91 and parts supported thereby are disposed on the outer surface of the forward wallof the head housing 68 whereby the rate of feed of the piston and therefore of the spindle carrier may This groove is adapted to have its.

be readily adjusted from the outside of the machine. The back-pressure valve mechanism I69 is substantially identical in construction with the balance valve mechanism I49 except that it operates in a reverse direction and for an opposite purpose to that of the balance valve I49. This back-pressure valve mechanism is illustrated structurally in Fig. 6 and as there shown comprises a valve sleeve 20I pressed into a suitable bore formed in one end of the bore in said sleeve closed by a screw plug or the like 202. The sleeve 20I is provided with a plurality of sets of radial ports 203, 204, and 205, each set being encircled by a similar circumferential groove 206 formed in the exterior of the sleeve 20I. Disposed within the bore in the valve sleeve is a valve member 201 having intermediate its ends a reduced portion or cannelure 208 adapted to control the rate of flow through the port 205 which, as will later be made clear, is the rate of flow from the discharge end of the cylinder during a tooling or cutting stroke of the tool carrier.

As seen in Fig. 19, the ports 208 and 205 have respectively connected therewith the branch discharge pipes or conduits I51 and I58 which through pipes or conduits I56, and I55, connect with the control valve mechanism 84, while ports 204 have connected therewith the discharge pipe or conduit I41. In order to normally control the position of the valve member 201 it has abutting one end thereof a spring 209 which encircles a. stem 2l0 projecting from an adjustable screw 2| I threaded into a bushing 2I2 in turn threaded into the lower end of the valve sleeve 20L By providing the adjustable sleeve 2I2, which forms the other abutment for the spring 209, and the adjustable screw 2, the tension and position of the said spring 209 may be varied. Each of these parts is adapted to be secured or locked in adjustable positions by suitable lock nuts threaded thereon.

Referring now to Fig. 19, it will be noted that the pipe or conduit I5I extending from the upper end of the cylinder 61, from which extendbranch pipes or conduits I89 and I50, terminates in an overload piston-valve mechanism indicated in general in Fig. 19 by the reference character 2I3. This overload mechanism is illustrated structurally in Fig. 'l and comprises a block 2I4 in which is provided a bore 2I5 which forms a cyline der for piston member 2I6. The block 2I4, see Fig. 19, is provided therethrough with a port 2" with which the end of the pipe or conduit I5I connects, The piston 2I6 has projecting from its lower end a rod 2I8 passing through the bore in a sleeve 2I9 threaded into the block 2I4 at the lower end of the bore therein. Surrounding the piston rod 2I8 is a spring 220 abutting on its upper end with the piston 2 I 6 and on its lower end with the sleeve 2I9. Below the block 2I4 the sleeve 2I9 is provided with a spur tooth pinion 22I meshing with the teeth of a worm 222. The worm 222 is integral with or secured to a shaft 223 rotatably journaled in a carrier 224 which is similar to the carrier I91 and is secured to'the outer surface of the head housing 68. The shaft 223 has pinned or otherwise secured thereto a knob 225 whereby the worm may be adjusted for rotating the sleeve 2I9 and thereby varying the tension placed on the spring 220.

This overload mechanism is adapted to effect the reversal of the valve control mechanism at the end of the tooling or drilling operation as the valve block I29 and having will be more clearly pointed outlater. To eflect this operation the piston rod 2I8 overlies a screw 226, see Figs. 6, '1, and 8, carried by a lever 221 keyed or otherwise secured to the shaft' I61 and disposed on the opposite side of the bracket I68 from that on which the latch I66 is disposed. In other words, the downward movement of the piston 2I6 through it's rod 2I8 and lever 221, shaft I61, and latch I66 removes the latch from the lug I10 thereby permitting the spring I63 to shift the control valve I42 to its upper position.

In order to overload the mechanism 2I3 the tool carrier is provided with a dog which limits the movement of the said carrier. As shown in Fig. 3, this dog is indicated by the reference numeral 228 having projecting therefrom a cy-, lindrical lug 229 in which is threadedly disposed the dog screw 230. The dog screw 230' is adapted to have its lower end 23I engage with a ledge or shoulder 232 integral with and projecting from the head housing 68 as seen in Fig. 11. To secure the dog 228 in position and hold same against movement when the main actuating piston 66 is overloaded, the carrier is provided adjacent the slot I I1 with a plurality of spaced rack teeth 232a engaging a hardened pawl 233 projecting rearwardly from the dog 228.

The operation of the mechanism thus far described is as follows:

The pump 80 is started to provide pressure in the pressure pipe or conduit 82 as determined by the relief valve 83. At this time the starting valve member 94 is in the position shown in the drawings with the control valve member I42 in its uppermost position thereby connecting the.

medium above the piston 66 is discharged through the pipes or conduits I5I and I50, control valve mechanism 64, and pipes or conduits I44a, I46a, and I41 to the sump or tank 19.

The lever I01 through its knob I08 is now actuated downwardly from the position shown in Fig. 3, thereby elevating or raising the starting valve member 94 to connect the ports 9| and 90 of the starting valve mechanism 96. At this time the pressure in the pipe or conduit 82 is connected through its branch pressure pipe or conduit 85, starting valve mechanism 86, and pipe or conduit 96 with the upper end of the control valve member I42 for actuating same downwardly to its lowermost position against the yielding resistance of spring I63 and loading said ber 94 to' the position illustrated in the drawings.

At this time the starting valve member 94 connects the ports 9I with 92 and cuts off the pressure through the branch pressure conduit 85 from the conduit 96. By this arrangement the upper end of the control valve member I42 is now connected through the pipe or conduit 96,

the latch I33 thereby positioning the valve memher as shown in the drawings.

At this time the pressure in the pipe or conduit- 02 is connected through the control valve mechanism 34 with the pipe or conduit I43, balance valve mechanism I 40, pipes or conduits I00 and I34, throttle valve mechanism I 01, and pipes or conduits I39 and III with the'cylinder 31 for actuating the piston 33 at a relatively slow or feeding rate through the work. The ofiier end of the cylinder is now connected through the pipes or conduits I54 and I03, control valve mech*- anism 34, pipes or conduits I05, I50, I51, and IN, back-pressure valve mechanism I 83, and pipe or conduit I41 with the sump or tank". -Due to the construction of the'balance valve mechanism I49 and back-pressure valve mechanism I59 the said piston 80 is actuated at a continuous rate depending upon the adjustment of the throttle valve mechanism I01, which rate is continued until the work is completely tooled or drilled.

At the conclusion of the tooling or drilling operation the dog screw 230 engages the ledge 232 thereby arresting any further movement of the tool carrier relative to the head. This means, of course, thatthe flow of hydraulic fluid through the system to the upper sideof the piston 30 is stopped and this causes a backing up of the pressure through the pipe or conduit III to the overload. mechanism 2I3. This backing up or building up of pressure in the overload cylinder 2|! eventually actuates the piston 2I3 therein downwardly against the yielding resistance of the spring 220 and causes the piston rod 2I3 to engage the screw 223 and actuate .the lever 221, shaft I61, and latch I03 rection and release the lug I10. As soon asthis occurs the spring I33 shifts the control valve member I42 to its uppermost position thereby, through the connections above described, connects the pump 30 with the under side of the piston 00 for elevating same and the parts carried thereby.

From the foregoing it willnow be appreciated that there has been provided an hydraulic control mechanism for effecting a rapid advance of the tool to the work, a slow movement of the tool through the work at a feeding rate, and a rapid retraction of the tool from the work. It should also be noted that the overload mechanism 2I3 effects a dwell in the movement of the tool between the feeding thereof and the retraction, which dwell may be utilized for clean-.

in accordance with the amount of rapid traverse to be had prior to the actual tooling operation and the'amount-of ally to be accomplished. v

It may at times be necessary or desirable to reverse the direction of movement of the tool and tool carrier without waiting for the completion of the tooling orcutting stroke. eflected manually through the handle or lever I01 by actuating same in a direction opposite to that in which it is moved for the movement of the parts. For this purpose the starting valve member stem I30 is provided at its lower end with a point 230 thereby providing an inclined or cam surface 231 which normally overlies and is spaced from a corresponding cam face 230 formed'on a block secured to the farthest end of the shaft I01. By reference to Figs. 6 to'9 inclusive it will be noted that if the starting valve member 94 were actuated downwardly, described, the cam face 231 would engage with the cam face 233 and actuate the block 230 in a counterclockwise direction .thereby correspond,-

-ingly oscillating or rocking the shaft I31 which will oscillate the latch I06 in a clockwise direction to free the lug I10 and permit the spring I63 to shift the control valve member I42 to the position for retracting the tool carrier. From this it will therefore be seen that the movement oithe tool carrier may be initiated by manual means in each direction. The foregoing description deals with a mechanism that may be termed a general purpose drilling machine in w ch work-pieces having relatively shallow holes are operated upon, If

it is desired to drill comparatively deep holes, or

relatively thick work-pieces, such as the oil holes in crank shafts and the like, it is desirable and in a clockwise diing up the face ofbosses or the like around a hole, or'for any other purposes for which a dwell useful. This dwell is, of course, adjustable through the mechanism by varying the tension on theoverload mechanism spring 220 and as will be later pointed out is utilized torelieve the overload thrust on drills during a drilling operation.

In order to permit a ready setting up of the machine the head housing 30, see Figs. 3 and 4, is provided adjacent the dog slot II1 with a depressed seat 234 in which is set a scale 23! graduated in accordance with the unit of measure and utilized for the initial setting of the parts even necessary to periodically withdraw the drill from the hole to permit a clearingof the previously formed chips and the like. In ,order to il'ect this operation automatically with the machine above described it is only .necessary to supply-a couple'of additional valves, mechanism, to connect the said valves with certain of the valves above described. These'additional valves are illustrated diagrammatically in Fig. 20 to which reference is now to be had.

As seen in Fig. 20, there is provided a valve mechanism indicated in general by the reference character 240 which may be termed a control valve for the timing mechanism indicated in general by the reference character 2. The timing mechanism control valve 240 is somewhat similar in construction to the starting valve mechanism 83 and is illustrated structurally in Fig. 12 and comprises a valve block 242 secured to the outer side of the valve block I29. Pressed into a suitable bore in the valve block 242 is a valve sleeve 243 having formed therethrough plurality of sets of radial ports 244, 240, and 240, each set of ports being encircled by a similar groove formed in the exterior of the sleeve 243. Disposed with. in the bore in the valve sleeve 243 is a valve member 243 having formed intermediate its ends 249 adapted,

initially starting through the lever I01 as above and coupling 1 The ports 244 have con'-' drilling or tooling actu- This may be 230 keyed or otherwise which terminates in the pipe or conduit 66 and thereby the sump or tank 19. The remaining ports 245 have connected therewith one end of a pipe or conduit 252 which terminates at a port 256 formed through the wall of the timing mechanism cylinder 254.

' The timing mechanism 24I is structurally illusstrated in Fig. 12 and as there shown comprises a bore formed in the valve block 242 and constituting the cylinder 254. Disposed within this cylinder 254 is a piston 255 from which projects a piston rod 256. The rod 256 passes through a guide sleeve 251 secured in the lower end of the cylinder 254. Encircling the piston rod 256 and disposed within the cylinder 254 is a spring 258 having its one end in abutment with the undersurface of the piston 255 and its other end in abutment with the guide sleeve 251.

In order to actuate the valve member 248 to its several operative positions the said valve member has projecting therefrom a valve stem 259 in which is formed a notch 260 receiving a lug 26I projecting from one end of a lever 262. The lever'262 is pivoted intermediate its ends to .6 a bracket 263 secured to the undersurface of the valve block 242. Projecting from the other end of the lever 262 is a lug 264 received in a notch 265 provided in one side of the member I62 carried by the control valve stem I60. From the foregoing it will be noted that the control valve member 248 for the timing mechanism and the control valve member I42 for the piston 66 are connected to one another whereby the movement of one of said members in one direction effects the movement of the other member in the opposite direction. In order to maintain the guide member and spring abutment I62 in proper position on the valve stem I the said member is provided on its side opposite from the notch 265 with a vertical guideway 266 receiving the guiding head 261 of a screw mounted in the valve sleeve 28I.

The timing piston rod 256, see Fig. 12, passes through the forked end 268 of a lever 269 integral with or secured to and projecting from the valve latch I66, and the said piston rod 256 is provided below the arm 269 with a pair of lock nuts 218 whereby the upward movement. of the piston 255 and its rod 256 actuate the latch I66 to release the main piston control valve member I42 for the purpose which will now be described.

From the foregoing description it will be noted that the upward movement of the main piston control valve I42 moves the time mechansim control valve member 248 downwardly thereby connecting the pressure in the pipe or conduit 62 through the pipe or conduit 250, valve mechanism 246, and pipe or conduit 252 with the time cylinder 254 for downwardly actuating the timing piston 255 therein. This takes place during the rapid movement of the carrier toward the work-piece, which movement is, of course, arrested or stopped by the rapid traverse dog shifting the starting valve mechanism and thereby permitting the main piston control valve member I42 to assume the position illustrated in the drawings. The movement of this control valve member to this position through the arm 262 and parts associated therewith shifts the time mechanism control valve member 248 to the position shown, thereby connecting the time cylinder 254 through the pipe or conduit 252, valve mechanism 246, and pipes or conduits 25I and 98 with the sump or tank 19, thereby permitting the upward movement of the time piston 255. During the takes place after a definite time interval, which time interval, ofcourse, is adjustable to permit the drill or tool to operate partway through a work-piece. As will later be described, the parts are automatically reversed whereupon the tool carrier is again actuated toward the work-piece.

In order to control the rate of movement of the time piston 255 the pipe or conduit 25I is provided with a needle valve adjustable to control the bleed or flow through the pipe, which valve is indicated in general in Fig. 20 by the reference character 21I. The needle valve 21I is shown structurally in Fig. 12 as a screw 212 having a pointed end 213 and threaded in a boss 214. The outer end of the screw 212 is notched and projects beyond the forward face of the head housing 68 and the said screw is further provided with a lock nut, 215 for securing same in adjusted positions.

As shown in Fig. 12, the needle valve is illustrated as controlling the discharge through a port in the valve block leading from the sleeve radial ports 244 and bleeding into a port 216 which in turn empties into the interior of the head housing.

From the foregoing it will be noted that there has been provided a mechanism whereby a tool carrier is automatically-hydraulically reversed after it has completed a part of its intended working stroke, whereupon the parts are again reversed to pass through this stroke. This structure would result in the drill slowly feeding through the space through which it previously passed and before it could again commence to effect a stock removal from the work, the tool carrier would be reversed. It is therefore necessary to provide a slightly modified control structure which will permit the tool carrier to move at a rapid rate through the distance previously tooled and at the end of this movement to again eifect a stock removal from the work. This mechanism is illustrated in Fig. 14 et seq. showing a slight rearrangement of certain of the control parts as well as mechanism for resetting the' rapid traverse dog at the conclusion of each workpiece. 'This mechanism comprises a bracket 211 secured to one side of the head housing and providing at its upper end a bearing 218 in which is rotatably journaled an oscillatable rod 219. The lower end of the rod 218 is oscillatably journaled in a second bearing 280 integral with and projecting from a modified cover plate 28I. Secured to the rod 219 at an adjustable point determined by the depth of cut or thickness of the work-piece is a collar 282. Disposed in the carrier slot II1 behind the rod 219 is the rapid traverse dog 263 secured in such a manner as to slide relative thereto as the carrier is being fed into the work. As shown in Fig. 23 the dog 283 is provided in its forward face with a recess 283m and/or having a lug 283D projecting from its rear surface into the slot. H1. The lug 28312 is provided with an aperture through which extends a stud 2830 having the opposite ends thereof threaded. The rear end of the stud receives on its threads a nut 283d and on the threads at its forward end receives a second nut 263e. The nut 283a is disposed in the dog recess 283a and has beneath it 8 anemia I This frictional clamping of the dog is insufiicient to restrain the movement of the carrier but is sumcient to throw the valve 'flipper member I24.

The flipper 124 has projecting therefrom a lug 2 received in a notch formed in. a block 2" from which depends a stem 2". The stem 28! is slidably disposed in a guide sleeve 2" carried by the cover plate 2" and said stem 22'! overlies a plunger 2" yieldably actuated by a spring 2" in one direction relative to a bearing sleeve 2M integral with a slide 222. The slide 292 is in turn disposed for axial movement relative to a carrier 2 integral with or secured to the cover plate. 22L The plunger 2|! is in turn disposed above an oscillatable lever or finger 294 which, as will be seen from Fig.14, may be oscillated about a pivot screw 20! to dispose a projection 29S thereon beneath the plunger 288. This finger 2 is yieldably actuated by the springpressed plunger 28'! disposed in a block 2 in the carrier. The slide 292 is provided substantially midway of-itslength with a slot 289 receiving the ball end 200 of an arm "I depending from the hub 302 of the manually actuable lever I". In addition, see Fig. 17, the slide 282 has near its one end a notch 3" receiving the ball end "I projecting from collar secured to the rod 21! at a point below the bearing 2". In addition the rod 219 carries near its upper end a detent plate 300 having formed therein a pair of notches 301 cooperating with spring-presseddetent pawl 3" carried by the bracket 21].

The operation of these parts is as follows:

The collar 282 is positioned at the desired point on the rod 219 and the flnal dog 228 is also positioned at the proper point depending upon the thickness of the work or the depth to which it is desired tooperate and the rapid traverse dog 2 lies positioned at the proper point to provide the initial amount of rapid traverse movement to be given the carrier. The manual lever I0! is then thrown to the rapid advance position for operating the starting valve mechanism as above described for initiating thedownward or forward movement of the tool carrier. This movement of the lever in addition to shifting the starting valve member shifts the slide 292 to the position shown in the drawings thereby oscillating the rod 219 and parts carried thereby to retract the point or end 3" of the collar 222 from the path of movement of the rapid traverse dog 283. The tool carrier and parts carried thereby now descend until the time mechanism effects a reverse thereof, whereupon the tool carrier is actuated upwardly at a rapid traverse rate. As soon as the tool carrier is fully retracted the finger. 294 engages and upwardly urges the spring pressed plunger 2 which in turn engages the stem 281 for shifting the block 2" upwardly and actuating the valve fiipper member I24 to a downward feeding position. This movement of the fiipper member I24 efi'ects a corresponding movement of the lever hub 302 and therefore the arm ill but due to'the loss of motion between the said lever end and walls of the slot 29! no movement of the slide 202. takes 'place. The carrier is now actuated at a rapid rate toward the work-piece. Thecarrier continues to move at this rate until it again reaches the point it was prior to the previous reversal, since the rapid traverse dog was shifted upwardly relative to the carrier during the preceding feeding stroke. During this rapidmovement of the carrierxthe time mechanism was again re-set and as soon as the rapid traverse dog shifts the parts to a feeding position the time cylinder comes into play to control the length of time the tool is permitted to operate before the carrier is again reversed. This repeated cycle of movement continues until the work is completely finished or tooled, whereupon the dog screw 230 acts on the block 286 to shift the slide 292 to the reverse position thereby oscillating the rod 218 to a position for interposing the corner 30! of the collar 282 in the path of movement of the rapid traverse dog 283 and arresting said dog in its upward movement when same reaches its initial point of adjustment. At this time when the carrier reaches the upper limit of its movement it is held in this position until it is again manually started on its downward stroke due to the manual actuation of the lever I 01. This arrangement is eifected because upon the shifting of the slide 292 the intermediate or spring plunger was shifted out of the path of the finger 284 and therefore the finger 294 was unable to eifect a reversal in the circuit through the valve operat- 1118 parts.

As will be appreciated, in deep hole drilling or the like considerable thrust may be developed on the drill due to the length of said drill being" encased in the material operated upon, which thrust may reach the point of twisting .or breaking the drill. To overcome this the overload spring 220 is somewhat released by backing up the guide sleeve 2| 9-t0 a point where the back pressure acting on the piston 2" will be such as to be Just above the normal cutting pressure. From this it will be seen that the drill or other tool may be withdrawn from the work as soon as the torque or thrust thereon reaches an unsafe point thereby materially increasing and prolonging the life of drills, tools, and the like which are hydraulically fed relative to work-pieces.

In Fig. 21 there is diagrammatically illustrated two general purpose machines each embodying the same mechanism illustrated in Fig. 19 and described in detail above. As will be seen in Fig. 19, a single pump 80 is employed for supplying both the rapid traverse and feed pressure. In a multiple spindle machine the occasion may arise when one of said spindles is to be rapidly advanced or retracted while the other is feeding and this may result in a loss of power to one or the other of the said machines thereby materially decreasing the efficiency thereof. In order to overcome this difilculty it is proposed to provide two pumps, one connected with the feed mechanism and indicated by the reference character 80 in Fig. 21, and a second pump 80' for supplying the rapid traverse and valve actuating fiuld. In this way there is no reduction of power to the spindle which is actually cutting or working while other spindles may be actuated at a pump on.

From the foregoing it is believed now evident that there has been provided a machine tool control mechanism which will accomplish the objects initially set forth above, and it will be noted that the machine performs all of the necessary and desirable functions for a machine of its which in actual practice are really ports interdrilled in the various valve blocks carrying the different valves and their operation mechanism except, of course, the pipes or conduits which extend from the pump and valve blocks.

What is claimed is:

1. In a machine tool, the combination of a tool carrier, hydraulic means for advancing and retracting said carrier, and a control mechanism for said hydraulic means including a control valve, 9. starting valve for. said control valve and operable for directly connecting a hydraulic pressure source therewith for shifting the same to effect the operation of the carrier at a rapidrate in a given direction; means associated and movable with said carrier for shifting the starting valve to relieve the hydraulic pressure on the control valve, spring means for shifting the control valve upon release of the pressure thereon to a position to effect continued movement of the carrier but at a slow rate of speed, latch means limiting the movement of the control valve by the spring means, and means operable for releasing the latch and effecting a further shifting of the control valve to effect a reverse movement of the carrier at a rapid rate.

2. In a machine tool, the combination of a'tool carrier, hydraulic means for advancing and retracting said carrier, and a control mechanism for said hydraulic means including a control valve, a starting valve for said control valve and operable for directly connecting a hydraulic pressure source therewith for shifting the same to effect the, operation of the carrier at a rapid rate in a given direction, means associated and movable with said carrier for shifting the starting valve to relieve the hydraulic pressure on the control valve, spring means for shifting the control valve upon release of the pressure thereon to a position to effect continued movement of the carrier but at a slow rate of speed, latch means limiting the movement of the control valve by' the spring means, and means operable for releasing the latch and effecting a further shifting of the control valve to effect a reverse movement of the carrier at a rapid rate, said latch releasing means including a hydraulic piston connected with the forward or feeding side of the tool carrier actuating means and operable upon building up of pressure on said forward side of the carrier feeding means.

3. In a machine tool, the combination of a tool carrier, hydraulic means for advancing and retracting said carrier, and a control mechanism for said hydraulic means including a control valve, a starting valve for said control valve and operable for directly connecting a hydraulic pressure source therewith for shifting the same to effect the operation of the carrier at a rapid rate in a given direction, means associated and movable with said carrier for shifting the starting valve to relieve the hydraulic pressure on the control valve, spring means for shifting the control valve upon release of the pressure thereon to a position to efiect continued movement of the carrier but at a slow rate of speed, latch means limiting the movement of the control valve by the spring means, means operable for releasing the latch and efiecting a further shifting of the control valve to efiect a reverse movement of the carrier at a rapid rate, said latch releasing means including a hydraulic piston connected with the forward or feeding side of the tool carrier actuating means and operable upon building up of pressure on said'forward side of the carrier feeding means, and dog means for stopping the movement of the carrierjat the conclusion of the working stroke to thereby cause a building up of pressure on the forward or feeding side of the carrier actuating means and effect the operation of the latch releasing piston.

4. In a machine tool, the combination of a support, a tool head secured to said support and having formed thereina dove tail guide-way, a

tool carrier having a guiding tongue projecting therefrom into the dove-tail guide-way of the tool head, a'hydraulic piston and cylinder mechanism connected with said carrier for effecting its reciprocation, and control means for said piston and cylinder mechanism including a control valve, 2. starting valve manually operable to a position for connecting a hydraulic pressure source with the control valve for shifting the same to cause a forward movement of the piston at a rapid rate, co-operating means on said carrier and associated with said starting valve and including a dog on the carrier for shifting said starting valve to a positionfor relieving the pressure on the control valve, spring means associated with the control valve for shifting same upon release of the hydraulic pressure thereon to a position to cause the continued forward movement of the piston, and cylinder mechanism but at a slow feeding rate, a pivoted latch for limiting the movement of the control valve by the spring means, and means for rendering the latch inoperative and effecting the further shifting of the control valve by the spring means including c0- operating stop dog means associated with the carrier and an abutment associated with the tool head for building up a pressure on the latch and releasably actuating same.

5. In a machine tool, the combination of a support, a tool head secured to said support and having formed therein a dove-tail guide-way, a

tool carrier having a guiding tongue projecting therefrom into the dove-tail guide-way of the tool head, a hydraulic piston and cylinder mechanism connected with said carrier for effecting its reciprocation, and control means for said piston and cylinder mechanism including a control valve, a starting valve manually operable to a position for connecting a hydraulic pressure source with the control valve for shifting the same to cause a forward movement of the piston at a rapid rate, co-operating means on said carrier and associated with said starting valve and including a dog on the carrier for shifting said starting valve to a position for relieving the pressure on the control valve, spring means associated with the control valve for shifting same upon release of the hydraulic pressure thereon to a position to cause the continued forward movement of the piston and cylinder mechanism but at a slow feeding rate, a pivoted latch for limiting the movement of the control valve by the spring means, and means for rendering the latch inoperative and effecting the further shifting of the control valve by the spring means including cooperating stop dog means associated with the carrier and an abutment associated with the tool head for building up a pressure on the latch and releasably actuating same, said dog means on the carrier being adjustably secured thereto whereby different distances may be established between it and the tool head abutment and an abutment screw adjustably carried by said dog to effect 15 minute adjustment of this distance between the stop dog and its abutment.

6. In a machine tool, the combination of a tool carrier, a hydraulic piston and cylinder mechanism having 'one of said parts stationary and the other movable and connected with the carrier, a hydraulic circuit for actuating said movable part and thereby the tool carrier, including a control valve, a starting valve for the control valve and operable to a position for directly connecting a hydraulic pressure source therewith to shift said control valve to cause a forward movement of the tool carrier at a rapid rate, an actuator associated with the starting valve, means associated with the carrier and movable therewith for shifting the actuator to position the control valve for relieving the pressure on the control valve, spring means for shifting the control valve to a position upon relief of the hydraulic pressure thereon to cause the forward movement of the carrier at a reduced rate, latch means for holding the control valve in its slow speed position, and a hydraulic timing device operable for rendering the latch inoperative movable part and thereby the tool carrier, in-

cluding a. control valve, a starting valve for the 7 control valve to a position upon relief of the hydraulic pressure thereon to cause the forward movement of the carrier at a reduced rate,

valve and operable to a position for directly connecting a hydraulic pressure source therewith to shift said control valve to cause a forward movement of the tool carrier at a rapid rate, an actuator associated with the starting valve, means associated with the carrier and movable therewith for shifting the actuator to position the control-valve for relieving the pressure on the means for rotating connected with the carrier,

arrears control valve-spring means for shifting the control valve to a position upon relief of thehydraulic pressure thereon to cause the forward movement of the carrier at a reduced rate, latch means for holding the control valve in its slow hydraulic timing device operthe same.

9. In a machine tool, the combination of a tool carrier, a tool head for supporting said carrier, a hydraulic piston and cylinder mechanism having one of said parts stationary and the other a starting valve for the control valve and operable to a position for directly connecting a hydraulic pressure source therewith to shift said relieving the pressure on the control valve, spring means for shifting the control valve to a position upon relief of the hydraulic pressure thereon to eifect the further shifting of the control valve and cause a retraction of the carrier at a rapid rate, and means associated with the carrier and head for shifting said starting valve to a position for again connecting the hydraulic pressure with valve to cause a further forward movement of the carrier at a rapid rate,

10. In a deep hole drilling machine of the class described, the combination of a 5 der mechanism, one of which parts is fixed and the other movable and connected with the carrier, hydraulic means for actuating the said movable part and thereby the carrier, and control means for said hydraulic actuating means for eflecting a plurality of cyclic movements of the carrier including a control valve; a starting valve therefor and operable to a position for directly connecting a hydraulic pressure source with the control valve to shift same to a first position and shifting this valve in: the control valve in its second position, means operable after a pre-determined time interval from the initial actuation of the carrier for releasing the latch-and effecting the shifting of the control valve to a third position to cause a retracting rapid movement of the carrier, and co operating means carried by the carrier and support for operating the starting valve actuator to shift said control valve to a position connecting the hydraulic pressure source with the control valve for shifting this valve to its first position and for again advancing the carrier at a rapid rate from a point ahead of the initial starting po nt.

11. In a deep hole drilling machine of the class dwcribed, the combination of a tool carrier, a support for the tool carrier, a piston and cylinder mechanism, one of which parts is fixed and the other movable and connected with the carrier, hydraulic means for actuating the said movable part and thereby the carrier, and control means for said hydraulic actuating means for effecting a plurality of cyclic movements of the carrier including a control valve, a starting valve therefor and operable to a position for directly connecting a hydraulic pressure source with the control valve to shift same to a first position and efiect a rapid forward movement of the carrier from an initial starting point, an actuator associated with the starting valve whereby it is operated, a dog frictionally mounted on the carrier for operating the actuator to shift the startin valve to a position for relieving the pressure on the control valve, means for shiftingthe control valve to a second position to cause the tool carrier to move at a slow rate of speed, a latch for holding the control valve in its second position, means operable after a predetermined time interval from the initial actuation of the carrier for releasing the latch and effecting the shifting of the control valve to a third position to cause a retracting rapid movement of the carrier, and co-operating means carried by the carrier and support for operating the starting valve actuator to shift said control valve to a position connecting the hydraulic pressure source with the control valve for to its first position and for again advancing the carrier at a rapid rate from a point ahead of the initial starting point, said frictionally mounted dog on the carrier being held against movement with the carrier after shifting the valve actuator to limit the forward movement of the carrier but movable therewith during the retracting movement of the carrier and operable on successive advancing movements of the carrier to change its rate from rapid to slow at substantially the point where the previous reversal took place.

12. In a deep hole drilling machine of the class described, the combination of a tool carrier, a support for the tool carrier, a piston and cylinder mechanism, oneof which parts is fixed and the other movable and connected with the carrier, hydraulic means for actuating the said movable part and thereby the carrier, and control means for said hydraulic actuating means for effecting a plurality of cyclic movements of the carrier including a control valve, a starting valve therefor and operable to a position for directly connecting a hydraulic pressure source with the control valve to shift same to a first position and effect a rapid forward movement of the carrier from an initial starting point, an actuator associated with the starting valve whereby it is operated, a dog frictionally mounted on the carrier 1 1 for operating the actuator to shift the starting valve to a position for relieving the pressure on the control valve, means for shifting the control valve to a second position to cause the tool carrier to move at a slow rate of speed, a latch for holding the control valve in its second'position, means operable after a predetermined time. in terval from the initial actuation of the carrier for releasing the latch and effecting the shifting of the control valve to a third position to cause a retracting rapid movement of the carrier, and coeoperating means carried by the carrier and support for operating the starting valve actuator to shift said control valve to a position connecting the hydraulic pressure source with the control valve for shifting this valve to its first position and for again advancing the carrier ata rapid rate from a point ahead of the initial start ing point, said frictionally mounted dog on the carrier being held against movement with the carrier after shifting the valve actuator to limit the forward movement of the carrier but movable therewith during the retracting movement of the carrier and operable on successive advancing movements of the carrier to change its rate from rapid to slow at substantially the point where the previous reversal took place, and a hydraulically actuated piston connected with the forward side 'of the piston and cylinder mechanism for rendering the latch means inoperative prior to the actuation thereof by the timing mechanism in the event of a build up of pressure on the forward side of the piston and cylinder mechanism.

13. In a deep hole drilling machine of the class described, the combination of a tool carrier, a

support for the tool carrier, apiston and cylinder for said hydraulic actuating means for effecting a plurality of cyclic movements of the carrier including a control valve, a starting valve therefor and operable to a position for directly connecting a hydraulic pressure source with the control valve to shift same to a first position and effect a rapid forward movement'of the carrier from an'initial starting point, an actuator associated with the starting valve whereby it is operated, a dog frictionally mounted on the carrier for operating the actuator to shift the starting valve to a position for relieving the pressure on the control valve, means for shifting the control valve to a second position to cause the tool carrier to move at a slow rate of speed, a latch for holding the control valve in its second position, means operable after a predetermined time interval from the initial actuation of the carrier for releasing the latch and effecting the shifting of the control valve to a third position to cause a. retracting rapid movement of the carrier, and co-operating means carried by the carrier and support for operating the starting valve actuator to shift said starting valve to a position connecting the hydraulic pressure source with the control valve for shifting this valve to its first position and for again advancing the carrier at a rapid rate'from a point ahead of the initial starting point, said frictionally mounted dog on the carrier being held against movement with the carrier after shifting the valve actuator to limit the forward movement of the carrier but movable therewith during the retracting movement of the carrier and operable on successive advancing tuation thereof by the rality of cyclic movements of movements of the carrier rapid to slow at substantially the point where the previous reversal took place, a hydraulically actuated piston connected with the forward side of the piston and cylinder mechanism for rendering the latch means inoperative prior to the actiming mechanism in the event of a build up of pressure on the forward side of the piston and cylinder mechanism, and means for adjusting the point at which the build up pressure becomes operative for actuating the latch.

14. In a deep hole drilling machine, the combination of a tool carrier, a support therefor, a piston and cylinder mechanism one of which parts is fixed while the other is movable and connected with the carrier, hydraulic means for actuating said movable part and therefore the carrier, and control means for eflecting a pluthe carrier from an intermediate point starting valve for initial starting point and an including a control valve, 2.

with the control valve to cause a rapid advance movement of the carrier, spring means for shifting said control valve to a first position for advancing the carrier at a slow rate and to a second position for retracting the carrier at a rapid rate, an actuator associated with the starting valve for actuating same, slip dog means on the carrier for operating the actuator in one direction, cooperating means on the carrier and support for operating the actuator in the other direction from the intermediate point, latch means for limiting I the operation 01' the control valve by the spring means at the point for advancing the carrier at a slow rate, and a hydraulically actuated timing device for releasing the latch to eflect the shifting of the control valve at a predetermined time interval after the slow forward movement of the carrier.

15. In a deep hole drilling machine, the combination of a tool carrier, a support therefor, a

vancing the carrier at a slow rate and to a second position for retracting the carrier at a rapid rate, an actuator associated with the starting port for operating the actuator in the other direction from the intermediate point, latch means for limiting the operation of the control valve by the spring means at the point for advancing the anism for releasing the latch thereof by the hydraulic time mechanism in the to change its rate from event of an overload on said forward side of the piston and cylinder. v

16. In a deep hole drilling machine. the combination of a tool carrier, a suppo t therefor, a piston and cylinder mechanism one of which starting valve actuator.after the completion or the tooling of each work piece for retracting the carrier.

17. In a deep hole drilling machine, the com-' bination of a tool carrier, a support therefor, a piston and cylinder mechanism one of which parts is fixed while the other is 

